using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        var list = new List<Test>() { new Test(1), new Test(2), new Test(3) };

        list.ForEach(PrintTestObject);

    }

    public static void PrintTestObject(Test obj)

    {

        Console.WriteLine(obj.ToString());

    }

}

​

public class Test

{

    private readonly int _value;

    public Test(int value)

    {

        _value = value;

    }

    public override string ToString()

    {

        return "Test2: " + _value;

    }

}